Is dkh and kh the same thing?

[grubsnaek]

im shot out rite now, and just cant think rite are these the same thing. cause i use a salifert Kh/Alk test kit, but not sure if im even doing this rite. three weeks ago it was reading 3.5 and today it was 4.8. seems low, shouldnt it be much higher? its going up. doing water changes regulary now. well actually not so much regulary just do it at the same time every week rather than random times or even missing a day. but if this is too low how can i get it up safely. my cal. is at 420. so thats alright for a mixed LPS and softies tank. but whats up with it.

 

[earlybird]

yep Kh refers to karbonate hardness (german) and put the "d" in front and you have degrees of carbonate hardness.

 

[dogstar]

dKH is a unit of measurment, used to measure KH...
If your test is useing dKH then should be around 10 dKH IMO

 

[veni vidi vici]

if you are getting reading at 3.5 Meq/l then you are right where your supposed to be.
2.5-4 meq/L
7-11 dKH
125-200 ppm CaCO3 equivalents

 

[veni vidi vici]

Units of Alkalinity
The various units used for alkalinity are themselves cause for confusion. The clearest unit, and that used by most scientists is milliequivalents per L (meq/L). For a 1 millimolar solution of bicarbonate, the alkalinity is 1 meq/L. Since carbonate takes up two protons for each molecule of carbonate, it "counts" twice, and a 1 millimolar solution of carbonate has an alkalinity of 2 meq/L.
A unit that is used by many kits and some industries involves representing alkalinity in terms of the amount of calcium carbonate that would need to be dissolved in fresh water to give the same alkalinity. Typically, it is reported as ppm calcium carbonate. Of course, it has nothing to do with calcium, and there may be no carbonate in the water at all. Nevertheless, it is frequently used. Since calcium carbonate weighs 100 grams/mole (100 mg/mmole), then a solution that has an alkalinity of 100 ppm calcium carbonate equivalent contains 100 mg/L calcium carbonate divided by 100 mg/mmole calcium carbonate = 1 mmol/L calcium carbonate equivalent. Since carbonate has 2 equivalents per mole, this 100 ppm of alkalinity is equivalent to 2 meq/L. So to convert an alkalinity expressed as ppm CaCO3 to meq/L, divide by 50.
Finally there is the German term dKH (degrees of carbonate hardness), or just KH (carbonate hardness).Strictly speaking, it is the same as the carbonate alkalinity (AC in equation 8). Unfortunately, it is a very confusing term, as it has nothing to do with hardness. Further, it has been corrupted by the marine aquarium hobby to mean the same as total alkalinity, and every test kit that tests for dKH with a single titration is giving total alkalinity. The only kit that I am aware of that even makes a distinction between carbonate alkalinity and total alkalinity is one of the Seachem kits (Reef Status: Magnesium, Carbonate, & Borate) and it thankfully doesn’t use the term dKH at all. Consequently, most hobbyists should think of dKH as simply another measure of total alkalinity. The results obtained with such a kit (dKH) can be divided by 2.8 to yield the alkalinity in meq/L.
-CHEMISTRY AND THE AQUARIUM by RANDY HOLMES-FARLEY

 

[grubsnaek]

yes like i said veni at first it was at 3.5 now its up some. put your saying im good. so im happy now. i have been at work all day wondering what i was coming home to.